I have a lingering question which stems from an answer that Igave to What hydrolyses aspirin within the digestive tract andblood stream?
When a drug or any other substance is absorbed into thebloodstream in the stomach or small intestine, it ultimately passesthrough the hepatic portal vein and into the liver sinusoids, whereit is processed by hepatocytes and introduced into the generalcirculation via the vena cava. In terms of metabolism, this is whatcauses a "first-pass" effect for drugs that are ingested.
For drugs that are delivered either by intravenous,intramuscular, or sub-lingually (as in the other Biology.SEquestion), this first-pass effect is avoided, and the drug isintroduced into the general circulation without being metabolizedby the liver first.
Even though the first pass is avoided, the blood in the bodystill makes its way back through the liver eventually via thehepatic artery, which is a branch off of the celiac artery.
The issue I still have is, does the incoming blood from thehepatic artery merge with the blood from the hepatic portal vein?If not, does the blood from the hepatic artery still interact withthe hepatocytes in some way? (it makes sense that it does, and Ihave also read that one of the main functions of the hepatic arterywas to deliver blood supply for the liver's metabolic needs) Ifthis is not the case, where in the body would these drugs that wereintroduced via IV, etc., be metabolized?
I have a lingering question which stems from an answer that Igave to What hydrolyses aspirin within the digestive tract andblood stream?
When a drug or any other substance is absorbed into thebloodstream in the stomach or small intestine, it ultimately passesthrough the hepatic portal vein and into the liver sinusoids, whereit is processed by hepatocytes and introduced into the generalcirculation via the vena cava. In terms of metabolism, this is whatcauses a "first-pass" effect for drugs that are ingested.
For drugs that are delivered either by intravenous,intramuscular, or sub-lingually (as in the other Biology.SEquestion), this first-pass effect is avoided, and the drug isintroduced into the general circulation without being metabolizedby the liver first.
Even though the first pass is avoided, the blood in the bodystill makes its way back through the liver eventually via thehepatic artery, which is a branch off of the celiac artery.
The issue I still have is, does the incoming blood from thehepatic artery merge with the blood from the hepatic portal vein?If not, does the blood from the hepatic artery still interact withthe hepatocytes in some way? (it makes sense that it does, and Ihave also read that one of the main functions of the hepatic arterywas to deliver blood supply for the liver's metabolic needs) Ifthis is not the case, where in the body would these drugs that wereintroduced via IV, etc., be metabolized?
